HackMD MCP Server has Server-Side Request Forgery (SSRF) vulnerability

Description

A Server-Side Request Forgery (SSRF) vulnerability that affects all users running the HackMD MCP server in HTTP mode. Attackers could exploit this vulnerability by passing arbitrary hackmdApiUrl values through HTTP headers (Hackmd-Api-Url) or base64-encoded JSON query parameters.

Recommendation

Update the hackmd-mcp package to the latest compatible version. Followings are version details:

• Affected version(s): >= 1.4.0, < 1.5.0
• Patched version(s): 1.5.0

References

• GHSA-g5cg-6c7v-mmpw
• CVE-2025-59155
• CWE-918
• CAPEC-310
• OWASP 2021-A10
• OWASP 2021-A6

Related Issues

• OpenList (frontend) allows XSS Attacks in the built-in Markdown Viewer - CVE-2025-50183
• Potential DoS when using ContextLines integration (GHSA-r5w7-f542-q2j4) - Vulnerability
• Predictable results in nanoid generation when given non-integer values - CVE-2024-55565
• happy-dom allows for server side code to be executed by a <script> tag - CVE-2024-51757

Tags:

npm

hackmd-mcp